• Biomedical Science Letters
• /
• v.25 no.2
• /
• pp.159-169
• /
• 2019

Breast cancer stem cells (BCSCs) in breast cancer cells have self-renewal ability and differentiation potential. They are also resistant to drugs after chemotherapy. To overcome this resistance, we designed negatively charged 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG)-based liposomes for drug delivery. These liposomes have enhanced the therapeutic effects of a range of antitumor therapies by increasing the cellular uptake and improving drug delivery to targets sites. In this study, we investigated whether DMPG-POPC liposomes, including the neutral lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholin (POPC), can specifically bind to MCF-7 breast cancer cells and increase cellular uptake compared with that by CHOL-POPC liposomes. We also estimated the cytotoxicity of DMPG-POPC liposomes encapsulated with both metformin (Met) and sodium salicylate (Sod) against breast cancer cells and BCSCs compared with that of the free drugs. Our results demonstrated that these dual drug-encapsulated liposomes significantly enhanced the cytotoxic and anti-colony formation abilities compared with individual drug-encapsulated liposomes or free drugs in BCSCs. Overall, our results suggest that DMPG-POPC liposomes containing two drugs (Met + Sod) show promise for synergistic anti-cancer therapy of breast cancer by increasing drug delivery efficiency into breast cancer cells and BCSCs.

• Analytical Science and Technology
• /
• v.30 no.2
• /
• pp.89-95
• /
• 2017

The thermodynamic functions for the binding of the peptide Substance P (SP) on the surface of lipid vesicles made of various types of lipids were obtained by using isothermal titration calorimetry. The reaction enthalpies measured from the experiments were -0.11 to $-4.5kcal\;mol^{-1}$. The sizes of the lipid vesicles were measured with dynamic light scattering instrument in order to get the correlation between the reaction enthalpies and the vesicle sizes. The bindings of SP on the lipid vesicles with diameter of 37 to 108 nm were classified into the enthalpy-driven reaction or the entropy-driven reaction according to the size of the lipid vesicles. For the enthalpy-driven binding reaction, the significance of the electrostatic interactions between SP and lipid molecules was affirmed from the experimental results of the DMPC/DMPG/DMPH and DMPC/DMPS/DMPH vesicles as well as the importance of the hydrophobic interactions between hydrophobic groups of SP and lipid molecules.